Dataset Identification:
Resource Abstract:
- description: The basis for these features is U.S. Geological Survey Scientific Investigation Report 2017-5024 Flood Inundation
Mapping Data for Johnson Creek near Sycamore, Oregon. The domain of the HEC-RAS hydraulic model is a 12.9 mile reach of Johnson
Creek from just upstream of SE 174th Avenue in Portland, Oregon to its confluence with the Willamette River. Some of the hydraulics
used in the model were taken from Federal Emergency Management Agency, 2010, Flood Insurance Study, City of Portland, Oregon,
Multnomah, Clackamas and Washington Counties, Volume 1 of 3, November 26, 2010. The Digital Elevation Model (DEM) utilized
for the project was developed from LiDAR data flown in 2015 and provided by the Oregon Department of Geology and Mineral Industries.
Bridge decks are generally removed from DEMs as standard practice. Therefore, these features may be shown as inundated when
they are not. Judgement should be used when estimating the usefulness of a bridge during flood flow. Comparing the bridge
to the surrounding ground can be more informative in this respect than simply looking at the bridge itself. Two model plans
were used in the creation of the flood layers. The first is a stable model plan using unsteady flow in which the maximum streamflow
is held in place for a long period of time (a number of days) in order to replicate a steady model using an unsteady plan.
The stable model plan produced the areas of uncertainty contained in the sycor_breach.shp shapefile. The second is an unstable
model plan that uses unsteady flow in which the full hydrograph (rising and falling limb) is represented based on the hydrograph
shape of the December 2015 peak annual flood. The unstable model plan produced the flood extent polygons contained in the
sycor.shp shapefile and the depth rasters and represents the best estimate of flood inundation for the given streamflow at
U.S. Geological Survey streamgage 14211500.; abstract: The basis for these features is U.S. Geological Survey Scientific Investigation
Report 2017-5024 Flood Inundation Mapping Data for Johnson Creek near Sycamore, Oregon. The domain of the HEC-RAS hydraulic
model is a 12.9 mile reach of Johnson Creek from just upstream of SE 174th Avenue in Portland, Oregon to its confluence with
the Willamette River. Some of the hydraulics used in the model were taken from Federal Emergency Management Agency, 2010,
Flood Insurance Study, City of Portland, Oregon, Multnomah, Clackamas and Washington Counties, Volume 1 of 3, November 26,
2010. The Digital Elevation Model (DEM) utilized for the project was developed from LiDAR data flown in 2015 and provided
by the Oregon Department of Geology and Mineral Industries. Bridge decks are generally removed from DEMs as standard practice.
Therefore, these features may be shown as inundated when they are not. Judgement should be used when estimating the usefulness
of a bridge during flood flow. Comparing the bridge to the surrounding ground can be more informative in this respect than
simply looking at the bridge itself. Two model plans were used in the creation of the flood layers. The first is a stable
model plan using unsteady flow in which the maximum streamflow is held in place for a long period of time (a number of days)
in order to replicate a steady model using an unsteady plan. The stable model plan produced the areas of uncertainty contained
in the sycor_breach.shp shapefile. The second is an unstable model plan that uses unsteady flow in which the full hydrograph
(rising and falling limb) is represented based on the hydrograph shape of the December 2015 peak annual flood. The unstable
model plan produced the flood extent polygons contained in the sycor.shp shapefile and the depth rasters and represents the
best estimate of flood inundation for the given streamflow at U.S. Geological Survey streamgage 14211500.
Citation
- Title HEC-RAS Model Boundary for Flood Inundation Maps for Johnson Creek at Sycamore gage, Portland, Oregon.
-
- creation Date
2018-06-08T04:06:53.067499
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- Linkage for online resource
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- name Dublin Core references URL
- URL: https://doi.org/10.5066/F75X273G
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- link function information
- Description URL provided in Dublin Core references element.
Linkage for online resource
- name Dublin Core references URL
- URL: https://doi.org/10.3133/sir20175024
- protocol WWW:LINK-1.0-http--link
- link function information
- Description URL provided in Dublin Core references element.
Metadata data stamp:
2018-08-06T23:09:10Z
Resource Maintenance Information
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- notes: This metadata record was generated by an xslt transformation from a dc metadata record; Transform by Stephen M. Richard, based
on a transform by Damian Ulbricht. Run on 2018-08-06T23:09:10Z
Metadata contact
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pointOfContact
- organisation Name
CINERGI Metadata catalog
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- electronic Mail Address cinergi@sdsc.edu
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eng
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Metadata standard for this record:
ISO 19139 Geographic Information - Metadata - Implementation Specification
standard version:
2007
Metadata record identifier:
urn:dciso:metadataabout:2c0e7318-f300-4b58-9af6-badcc5f2fadb
Metadata record format is ISO19139 XML (MD_Metadata)